This invention relates to an apparatus for identification of light-wave emitters or, optionally, radio transmitters by simulation of their emission or transmission characteristics. More in particular, the invention relates to an apparatus for identification of light beacons or other light signals such as fixed buoys and lightships used particularly for maritime navigation, and of sound signals, for example, radio beacons.
It is known that when a ship is at sea at night, the navigator fixes its position from the angles at which he observes a certain number of light beacons, typically two or three, which he has previously identified. However, this identification can prove to be laborious and uncertain because there is great variety in light beacons in regard to their color, their periods, their rhythm, etc. Some of them are alike which can cause confusion, particularly when the navigator is tired, tensed or upset and/or in case of rough seas. Also, by day and by night, particularly during mediocre visibility, the navigator can fix the position of his ship from radio waves transmitted by a certain number of radio beacons, and the risks of erroneously identifying them is also present, for the same reasons as above.